Lubricant



Patented Oct. 24, 1944 LUBBIGANT No Drawing. Application March 31, 1942, Serial No. 436,968

13 Claims.

This invention relates to the use of metal derivatives of sulfurized compositions obtained or derived from cashew nut shell oil in hydrocarbon oils, particularly .petroleumoils, to improve the properties of lubricants compounded therewithf It is generallyrecognized that the recent developments in the automotive industry directed toward the increase in power output and emciency of mechanical equipment have set up such severe and exacting operating conditions as to necessitate an improvement in the highly refined hydro-- the highly refined hydrocarbon oils proportions of additive ingredients possessing inhibiting properties.

The natural occurring cashew nut shell oil is described in Matiello, J. J Protective 8: Decorative Coatings, Chap. 2 (1941?, as containing approximately 90% anacardic acid (CzzHazOa) and 10% cardol (C32H52O4) when extracted from the shells by means of solvents. This composition is very unstable and is subject to polymerization, condensation and decomposition on heating.

The usualv commercial methods of extracting the oil from the cashew nut shells are incidental to the extraction of the kernel. The cellular structure of the shell is destroyed by a thermal treatment such as a charring or carbonizing process which expels the oil and facilitates removal of the kernel. The extracted shell oil is collected as a dark, thick, viscous liquid whose chemical composition varies in accordance with the degree of heat used in the extraction process.

small quantity of an oil-soluble or oil-miscible metal derivative of sulfurized cardanol to a refined hydrocarbon oil provides a lubricant or a compounding lubricant which possesses improved detergent and anti-oxidant or anti-corrosiv properties, I The refined hydrocarbon oils which may be improved by the compositions of thepresent. invention include the petroleum lubricating oils used as motor, Diesel, turbine and aviation oil and the hydrocarbon oils used inthe preparation of industrial lubricants, greases, textile oils, etc.

Distillation of the commer'cialcashew nut shell oil carried out either at greatly reduced pressure or steam distillation at atmospheric pressure yields a distillate consisting almost entirely of cardanol. Cardanol distills over as a light colored liquid at approximately 225 C. and 10 mm. mer cury. Thiscompound is described as 'a phenol derivative possessing an unsaturated alkyl radical in the meta position. This compound is very unstable and upon heating forms condensation -possessing a nicotine-like odor which rapidly These thermally extracted oils are described as consisting primarily of anacardic acid, cardanol (czormo) and cardol with .cardanol predominating. .The particular proportions of these components vary in accordance with the amount of heat used in the extraction process as, for example, when extracting at low temperatures of approximately 400 F'., the extracted oil contains approximately 70% ,cardanol, whereas extracting at roasting temperatures yields an oil containing approximately 40-50% .cardanol.

It has been discovered that'the addition or a 'darkens when exposed to the atmosphere. This fraction which amounts to about 5% of the original oil contains approximately 0.64% nitrogen.

If desired, this lower boiling fraction may be removed by fractional distillation, I

Another method of obtaining cardanol is the destructive distillation of the solvent extracted cashew nut shell oil. The yields obtained will vary according to the degree of decomposition of the solvent extracted oil. The following physical constants were obtained on two distillates of the commercially available thermal extracted cashew nut shell oil, one being obtained by vacuum distillation at 10 mm. Hg (A). and the other by steam distillation at atmospheric pressure (3 action No Saponiiication No Per cent suliur The term "cardanoP as used throughout the specification and claims, unless otherwise stated, is meant to include not only the specific compound which has a constant boiling point at approximately 225 C. and 10 mm. Hg, but also the distillation products obtained by the distillaoil'at reduced pressures or by steam distillation at atmospheric or reduced pressure and the distillate obtained by the destructive distillation of the solvent extracted cashew nut shell oil.

- The particular. metals which may be used to form the oil-soluble metal derivatives of the present invention'include any of the following metals:

' particularproportions used dependupon the type r of lubricant tobeimpr'oved, the service for which the lubricantis intended, and the degree of improvement desired in the hydrocarbon oil. The

preferred range of proportions in a mineral lubricating oil when used in afewof the more common services are as follows:

Per cent by weight of finished lubricant Diesel lubricating oil 0.5 -1.0 -M otor'lubricating oil 0.3 -0.6 Heavy duty lubricating oil 0.5 -2.5 Turbine lubricating oil 0.01-0.1 Airplane lubricating oil' 0.2 0.6.

When preparing the oil-soluble additive ingredients in the presentinvention, such methods and conditions of reaction must be chosen which will avoid. the formation of polymerization and condensation products and insure the formation of' an oil-soluble product. In the present instance it ispreferable to first stabilize the cardanol by reducing the degree of unsaturation through partial hydrogenation." This may be done -.either. prior to or simultaneously with the formation of the metal derivative or prior to the sulfurization reaction depending upon which sew quence of reactions is used. This inventionis not limited to these particular methods of preparation, and any other classical methods may be used together with any sequence. of reactions which result in the formation of oil-soluble or oil-miscible metal derivatives cardanol.

If it is desired to prepare the metal derivative of sulfurized prior to sulfurization, the cardanol may be initially subjected to partial hydrogenation, such as hydrogenation with ,Raney. nickel catalyst under pressure, or simultaneously hydrogenated during the neutralization reaction by reacting the cardanol with -a solution of the desired" metal in liquid ammonia. In the latter reaction the residual hydrogen displaced by the metal partially hydrogenates the unsaturated constituents.

If, on the other,hand,' the sulfurization reaction precedes the neutralization step, particular care must be taken to insure an oil-soluble product. In the usual reaction of sulfur 'with car'- danol, polymerization products are obtained which range from semi-solid to solid rubbery materials'which are oil-insoluble. This type of reaction is to be avoided since the metal derivatives of these types of compositions are usually also oil-insoluble. However, if prior to the sulfurization *reactionthe cardanol was partially hydrogenated, the tendency toward the formation of polymerization products is reduced to a minimum.

tion of the thermal extracted cashew nut shell Although it is preferred to use the foregoing stabilizingreactions prior to sulfurization, other methods can be employed. One of these methods which avoids the hydrogenation step is the direct sulfurization withsulfur, at low temperatures, inthe presence of solvent diluents such as lubricating oil, xylenes, etc. In every instance, the amount of sulfur which may-be incorporated into the unsaturated constituents of cardanol will depend, upon the-degree of unsaturation.

The following examples illustrate two of the methods which might be used in'preparing the foregoing types of compounds:

EXAMPLE I tained from the distillation of commercially tion filtered to remove excess'calcium and other available cashew nut shell oil was charged in a hydrogenation bomb with' 10-15 grams of Raney nickel catalyst and treated withhydrogen under pressure. The temperature was controlled by external heat and varied between 50 F, at the start to 200 F. near-the end. The product, after being freed of catalyst and solvent, weighed 495 grams and had a bromine number of 80.

.533 grams of the partially hydrogenated product was added to 84 grams of sulfur in 750 cc. of xylene and stirred together. This mixture was then heated for seven hours at 140-150" F. To the resulting sulfurized product 175' grams of anhydrous barium hydroxide in 500 cc. of toluene were added. The mixture was heated to refluxing temperature under an automatic water separator until no more water was evolved. The slight excess of barium hydroxide was filtered out and the solvent was subsequently removed by distillation in vacuo. A sample of the resulting barium derivative analyzed 27.0% ash, 9.03% sulfur and 18.8% barium.

Exmru: II

. 415 grams of cardanol (bromine number 105) vigorous agitation over a period of two hours, After the addition was complete, the ammonia was allowed to boil off and the residual toluene soluimpurities. 'The solvent was removed by dis tillation invacuo and the product convertedto a- 50% concentrate by dissolving it in an equal weight of lubricating oil. The concentrate analyzed 3.6% calcium and had abromine number of 45. This corresponds to a decrease in unsaturation equivalent to the amount of hydrogen displaced by the calcium.

A mixture of 1160 grams of a 25% concentrate of the calcium derivative of partially hydro genated cardanol in lubricating oil, 16 grams of v sulfur and 500 cc. of xylene were heated with stirring to 150C. and maintained at that temperature for two hours. The xylene was subsequently removed by distillation in vacuo and the. resulting 25% concentrate analyzed 1.86% calcium I j and 1.78%. sulfur.

, The effectiveness-of the compositions of the present invention as improving agents for lubricants was demonstrated by empirical tests, together with tests in actual automotive engines. The following empirical test was designed. to ll-' lustrate the anti-oxidant or anti-corrosive properties of the additive ingredient in a lubricating issued by the Caterpillar Tractor Company. This test was carried out in a single cylinder Diesel engine operating at 900 R. P. M. with a, water jacket temperature of 175 F. The test wasrun continuously for 480 hours at increments of 120 hours or until rings are stuck as indicated by the increase in blow-by. The crankcase oil was drained every sixty hours and fresh oil added thereto. At the end of each test period, the engine was thoroughly examined and any carbonaceous deposits, lacquer and sludge formation, etc. werenoted and the principal engine parts "classified according to their condition. In'the present in-.

oil. This test consistsof a copper-lead bearing Reference oil specimen encased in a special non-wearing bushing, rotatively mounted an stainless steel shaft Engmapm Q 120 hours whom and immersed in a glass potof the oil to be tested.

Both fine structure and coarse structure coppermm Normalflfi Normal lead bearing specimens were used. The oil was ionizing above heat groove g.

heated to a controlled temperature of either 250 ig, $83,325: F. or 350 F. and continuously circulated between 5 55 m g.

I the bearing specimen and the shaft for hours. if? f ff Throughout the test the oil wascontinuously agi- 10 fiig e fi tated by means of copper baiiles which acted as e 3, 5 Q53 oxidation accelerators. The bearing specimen slig t sludge. lslcguer on was weighed before the test and after the 10- Rings #1, 2, aum; #5 #lstuclk'm's, hour period and the loss of weight recorded in v I xseggciticky, c t e; #4. 5 milligrams. The reference oil of this test was a Bearing 5 Y solvent refined, dewaxed, Mid-Continent lubrieating oil of an S. A. E. 30 grade. The following Reference oil plus 0.5% barium salt of sulfurized partially hydrogenated cardanol (Example I) Engine part 120 hours 240 hours 360 hours 480 hours Piston crown Scufling above heat groove Heat groove Ring grooves Piston skirt Under piston deposit... Filter B. Ringlands A B- B B, Ring cleanliness #1, 2, 3, 6 clean; #4l cq er on #l,2,3clea #4lacquer: #l,2,3clean; #4lacquer; #1, 2, 3 clean; #4, 5 15- top; #5 trace lacquer on top. #5, 6 light lacquer. #5, 6 light lacquer. quer; #6 varnish. Oil holes open. Rings stuck None Noam Bearing weight loss, grams 0,030,

results were obtained on the uninhibited reference oil and the reference oil compounded with the E i t R H C (H. additives of the present invention. a 1

Bearing corrosion-copper-lead (10 hours) A No scuffing to very fine soumng.

- Scufllng above heat 13 Up to sculfed. [Loss of weight, mgs.] groove. 0 Up to 75% scuffed.

v D Over 75% scufled. 250 F 350 F so %o '0$ 1 p 13 ll Heat 0 Up to 75 hite. 4- o 171 142 .2 81 h i can 0 BBVY acquer. lumen 9-15 l 250-275 Ring groove B Slight carbon in N05, 1 and 2, Relerence oil+0.5% barium salt of sulfurized C Heavier deposits.

artially hydrogenated cardanol (Example A Cleantoveryslight trace of varnish. g M 47-76 Piston Skirt B Trace varnish to light varnish. Reference oil+0.5% calcium salt of sulfurized 0 Heavy varnish to lacquer.

partially hydrogenated cardanol (Example D Very heavy lacquer.

I). 1 0 132 A Clean to discoloration.

1 Under piston deposit. B Trace deposit.

. Cv Heavy deposit. I Coarse structure. A Clean to mesh pattern visible.-

Filter B Mesh pattern visible to slight AS 8. test to indlcate the effectiveness of the 50 C amount nsid sludg e d additive ingredients of the present invention m 9 9 v under actual operating conditions in. an auto England A Clean to heav varnish. motive engine, a special test was devised which is B Heavy a modification of the test described in Diesel Lubricant Test Manual. Laboratory t as The hydrocarbon oils to which the oil-soluble metal derivatives of the present invention are added may be either in the crude form or partially or highly refined and may contain other additive ingredients such as-dyes, metal soaps,

- be made without departing from the spirit and scope thereof and, therefore, only such limita-' pour depressants, thickeners, V-. I. improvers, oiliness agents, extreme pressure agents, sludge dispersers,.oxidation inhibitors, and corrosion inhibitors such as sulfurized hydrocarbons, etc.

Obviously many modifications and variations of the invention, as hereinbefore set forth, may

' 2. A lubricant comprising a mineral lubricatoil and.0.01-5.0% by weight of an oil-soluble alkaline earth metal derivative of sulturized cardanol.

4; A lubricant comprising a mineral lubricating oil and 0.01-5.0% by weight of an oil-soluble al- 8. A lubricant comprising a hydrocarbon oil and 0.01-5.0% by weight of an oil-soluble alkaline earth metal derivative of sulfurized partially'hydrogenated cardanol.

9. A lubricant comprising a mineral lubricating oil and 0.0l-5.0% by weight of a tin derivaing oil and 0.01-5.0% by weight or a tin derlva-' kaline earth metal derivative of sulfurized, par-. 1 0 tive of sulfurized partially hydrogenated cardanol,

tially hydrogenated cardanol.

5. A lubricant comprising a hydrocarbon oil having incorporated therein 0.01-5.0% by weight of an oil-soluble metal derivative of sulfurized cardanol. v

6. A lubricant comprising a hydrocarbon oil having incorporated therein 0.01-5.0% by weight of .an oil-soluble metal derivative of sulfurized' partially hydrogenated cardanol.

11. A lubricant comprising a mineral lubricating oil and 0.01-5.0% by weight of a zinc derivative of sulfurized cardanol.

12. A lubricant. comprising a mineral lubricat l8 ing oil and OBI-5.0% by weight of a zinc derivative of sulfurized partially hydrogenated cardanol.

13. A lubricant "comprising a hydrocarbon oil and a small quantity of an oil-soluble metal derivative of sulfurized cardanol, said quantity :0 being suflicient to impart anti-oxidant properties to said hydrocarbon oil-constituent.

JOHN A. PATTERSON. RUSH F. MCCLEARY. 

